package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    @Resource
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Override
    public Result isFollow(long id) {
        //获得当前用户id
        Long userId = UserHolder.getUser().getId();
        //查询是否关注博主
        Integer count = query().eq("user_id", userId).eq("follow_user_id", id).count();
        return Result.ok(count!=null&&count!=0);
    }

    @Override
    public Result follow(long uid, boolean flag) {
        //获得当前用户id
        Long userId = UserHolder.getUser().getId();
        String key="follows"+userId;

        if(flag){
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(uid);
            boolean isSuccess = save(follow);
            if (isSuccess) stringRedisTemplate.opsForSet().add(key,String.valueOf(uid));
        }else {
            boolean isSuccess = remove(new QueryWrapper<Follow>().eq("user_id", userId).eq("follow_user_id", uid));
            if(isSuccess)stringRedisTemplate.opsForSet().remove(key,String.valueOf(uid));
        }
        return Result.ok();
    }

    @Override
    public Result followCommons(long uid) {
        //得到当前用户与该用户的关注列表key
        String key1="follows"+UserHolder.getUser().getId();
        String key2="follows"+uid;
        //求两个用户的交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key1, key2);
        if(intersect==null|| intersect.isEmpty())return Result.ok(Collections.emptyList());
        List<Long> ids = intersect.stream().map((i) -> Long.valueOf(i)).collect(Collectors.toList());
        List<UserDTO> users = userService.listByIds(ids).stream().map((u)->{
           return BeanUtil.copyProperties(u,UserDTO.class);
        }).collect(Collectors.toList());
        return Result.ok(users);
    }
}
